Hydrocyanation method for ethylenically unsaturated organic compounds

ABSTRACT

The invention concerns a method for hydrocyanation of ethylenically unsaturated organic compounds into compounds comprising at least a nitrile function. More particularly, it concerns a method for hydrocyanation of organic compounds comprising at least a ethylenical bond by reacting hydrogen cyanide, in the presence of a catalytic system comprising a transition metal and an organophosphorus ligand. The organophosphorus ligand is a compound with monophosphanorbornadiene structure. The invention concerns in particular hydrocyanation of butadiene into adiponitrile.

[0001] The present invention relates to a process for the hydrocyanationof organic compounds comprising ethylenic unsaturation to compoundscomprising at least one nitrile functional group.

[0002] It relates more particularly to the hydrocyanation of diolefins,such as butadiene, or substituted olefins, such as alkenenitriles, forexample pentenenitriles.

[0003] French Patent No. 1 599 761 discloses a process for thepreparation of nitrites by addition of hydrocyanic acid to organiccompounds having at least one ethylenic double bond in the presence of anickel catalyst and a triaryl phosphite. This reaction can be carriedout in the presence or absence of a solvent.

[0004] When a solvent is used in this process of the prior art, it ispreferably a hydrocarbon, such as benzene or xylenes, or a nitrile, suchas acetonitrile.

[0005] The catalyst employed is an organic nickel complex comprisingligands such as phosphines, arsines, stibines, phosphites, arsenites orantimonites.

[0006] The presence of a promoter for activating the catalyst, such as aboron compound or a metal salt, generally a Lewis acid, is alsorecommended in the said patent.

[0007] Patent FR-A-2 338 253 provided for the implementation of thehydrocyanation of compounds having at least one ethylenic unsaturationin the presence of an aqueous solution of a compound of a transitionmetal, in particular nickel, palladium or iron, and of a sulphonatedphosphine.

[0008] The sulphonated phosphines disclosed in this patent aresulphonated triarylphosphines and more particularly sulphonatedtriphenylphosphines.

[0009] This process makes possible correct hydrocyanation, in particularof butadiene and pentenenitriles, and easy separation of the catalyticsolution by simple separation by settling and consequently prevents asfar as possible discharge of effluents or waste comprising the metalsacting as catalyst.

[0010] However, research is being carried out to find novel catalyticsystems which are more effective both as regards catalytic activity andas regards stability.

[0011] One of the aims of the present invention is to provide a novelfamily of ligands which makes it possible to obtain, with transitionmetals, catalytic systems exhibiting an improved activity with respectto the known systems.

[0012] To this end, the invention provides a process for thehydrocyanation of organic compounds comprising at least one ethylenicbond by reaction with hydrogen cyanide in the presence of a catalyticsystem comprising a transition metal and an organophosphorus ligand,characterized in that the ligand is a phosphine corresponding to thefollowing general formula:

[0013] in which:

[0014] E represents O or S;

[0015] n represents 0 or 1;

[0016] R₁, R₄, R₅ and R₆, which are identical or different, represent ahydrogen atom; an optionally substituted, saturated or unsaturated,aliphatic hydrocarbonaceous radical comprising 1 to 40 carbon atoms, thehydrocarbonaceous chain of which is optionally interrupted by aheteroatom; an optionally substituted, monocyclic or polycyclic,saturated, unsaturated or aromatic, carbocyclic or heterocyclic radical;or a saturated or unsaturated, aliphatic hydrocarbonaceous radical, thehydrocarbonaceous chain of which is optionally interrupted by aheteroatom and carries a carbocyclic or heterocyclic radical as definedabove, the said radical optionally being substituted;

[0017] or else R₄ and R₅ form, together with the carbon atoms whichcarry them, an optionally substituted, saturated or unsaturated,carbocyclic monocycle preferably having from 5 to 7 carbon atoms;

[0018] R₂ represents a hydrogen atom or the X radical;

[0019] R₃ represents the X radical or the Y radical;

[0020] it being understood that one and one alone of the R₂ and R₃substituents represents the X radical;

[0021] X being chosen from a monocyclic or bicyclic, aromaticcarbocyclic or heterocyclic radical having from 2 to 20 carbon atoms; a1-alkenyl radical optionally exhibiting one or more additionalunsaturations in the hydrocarbonaceous chain and having from 2 to 12carbon atoms; a 1-alkynyl radical optionally exhibiting one or moreadditional unsaturations in the hydrocarbonaceous chain and having from2 to 12 carbon atoms; or a —CN, [(C₁-C₁₂) alkyl]carbonyl, [(C₃-C₁₈)aryl]carbonyl, [(C₁-C₁₂)alkoxy]carbonyl, [(C₆-C₁₈)aryloxy]carbonyl,carbamoyl, [(C₁-C₁₂)alkyl]carbamoyl or [di( C₁-C₁₂)alkyl]carbamoylradical; and

[0022] Y taking any one of the meanings of R₁;

[0023] R₇ has the meaning of R₁, R₄, R₅ and R₆ or represents ahydrocarbonaceous radical comprising a carbonyl functional group or aradical of following formulae:

[0024] in which,

[0025] A represents a hydrogen atom; (C₁-C₁₀)alkyl; or (C₆-C₁₀)aryl or(C₆-C₁₀)aryl(C₁-C₁₀)alkyl in which the aryl part is optionallysubstituted by one or more radicals chosen from (C₁-C₆)alkyl, (C₁-C₆)alkoxy, trifluoromethyl, halogen, di(C₁-C₆)alkylamino,(C₁-C₆)alkoxycarbonyl, carbamoyl, (C₁-C₆)alkylamino-carbonyl anddi(C₁-C₆)alkylaminocarbonyl;

[0026] —Ar₁—Ar₂— represent:

[0027] either the divalent radical of formula:

[0028] in which each of the phenyl nuclei is optionally substituted byone or more Z groups as defined below;

[0029] or the divalent radical of formula:

[0030] in which each of the phenyl nuclei is optionally substituted byone or more Z groups as defined below;

[0031] Z represents (C₁-C₆)alkyl, (C₁-C₆)alkoxy, trifluoromethyl,halogen, (C₁-C₆)alkoxycarbonyl, di(C₁-C₆)alkylamino,(C₁-C₆)alkylaminocarbonyl or di(C₁-C₆) alkylaminocarbonyl;

[0032] R₈ and R₉, which are identical or different, represent asubstituted or unsubstituted aryl radical.

[0033] This family of phosphine compounds is disclosed in French PatentApplications Nos. 2 785 610 and 2 785 611. Examples of a process for themanufacture of these compounds are also disclosed in the abovementioneddocuments.

[0034] Among the compounds described, the compounds corresponding to theformula (I) in which:

[0035] R₁, R₂, R₄, R₅ and R₆ independently represent a hydrogen atom orelse a T radical chosen from:

[0036] a saturated or unsaturated aliphatic hydrocarbonaceous radicalhaving from 1 to 12 carbon atoms, the hydrocarbonaceous chain of whichis optionally interrupted by a heteroatom chosen from O, N and S;

[0037] a monocyclic carbocyclic radical which is saturated or whichcomprises 1 or 2 unsaturations in the ring, having from 3 to 8 carbonatoms;

[0038] a saturated or unsaturated bicyclic carbocyclic radical composedof 2 single rings condensed to one another, each single ring optionallycomprising 1 to 2 unsaturations and exhibiting from 3 to 8 carbon atoms;

[0039] a mono- or bicyclic (C₆-C₁₀) aromatic carbocyclic radical;

[0040] a saturated, unsaturated or aromatic 5- to 6-membered monocyclicheterocyclic radical comprising 1 to 3 heteroatoms chosen independentlyfrom N, O and S;

[0041] a saturated, unsaturated or aromatic bicyclic heterocyclicradical composed of two 5- to 6-membered single rings condensed to oneanother, each single ring comprising 1 to 3 heteroatoms chosenindependently from O, N and S; and

[0042] a saturated or unsaturated aliphatic hydrocarbonaceous radicalhaving from 1 to 12 carbon atoms, the hydrocarbonaceous chain of whichcarries a carbocyclic or heterocyclic monocyclic radical as definedabove,

[0043] the said T radical optionally being substituted, are particularlypreferred.

[0044] Preferably, X is chosen from a (C₂-C₆)alkenyl group, a(C₂-C₆)alkynyl group, phenyl, naphthyl, thienyl, furyl, pyrrolyl,imidazolyl, pyrazolyl, thiazolyl, oxazolyl, pyridyl, pyrazinyl,pyridazinyl, isothiazolyl, isoxazolyl, benzofuryl, benzothienyl,indolyl, isoindolyl, indolizinyl, indazolyl, purinyl, quinolyl,isoquinolyl, benzoxazolyl, benzothiazolyl and pteridinyl.

[0045] Among the latter, the compounds comprising a T radical optionallysubstituted by (C₁-C₆)alkyl, (C₂-C₆) alkenyl, (C₁-C₆) alkoxy or(C₂-C₆)acyl; a radical chosen from: —R_(a)—COOR_(b), —R_(a)—NO₂,—R_(a)—CN, di(C₁-C₆)alkylamino, di(C₁-C₆)alkylamino (C₁-C₆)alkyl,—R_(a)—CO—N (R_(b))₂, —R_(a)-hal, —R_(a)CF₃ and —O—CF₃ (in which R_(a)represents a bond or (C₁-C₆)alkylene, R_(b), which are identical ordifferent, represent a hydrogen atom or (C₁-C₆) alkyl, and halrepresents halogen);

[0046] or alternatively the radical:

[0047] where R_(d) is chosen from (C₁-C₆)alkyl, (C₂-C ₆)alkenyl,(C₁-C₆)alkoxy, (C₂-C₆)acyl, —R_(a)—COOR_(b), —R_(a)—NO₂, —R_(a)—CN,di(C₁-C₆)alkylamino, di(C₁-C₆)alkylamino (C₁-C₆) alkyl, —R_(a)—CO—N(R_(b))₂, —R_(a)-hal, —R_(a)—CF₃ and —O—CF₃ (in which R_(a), R_(b) andhal are as defined above);

[0048] m represents an integer between 0 and 5;

[0049] R_(c) represents a bond, (C₁-C₆)alkylene, —O—, —CO—, —COO—,—NR_(b)—, —CO—NR_(b)—, —S—, —SO₂— or —NR_(b)—O—, R_(b)being as definedabove, are particularly preferred.

[0050] Mention may be made, as preferred compounds of the invention, ofthe compounds of following formulae (II) or (III):

[0051] Formula (II):

[0052] Formula (III):

[0053] Transition metal compounds, more particularly nickel, palladiumand iron compounds, are used as transition metal.

[0054] The compounds which are the most preferred among theabovementioned compounds are nickel compounds.

[0055] Mention may be made, as nonlimiting examples, of:

[0056] compounds in which the nickel is in the zero oxidation state,such as potassium tetracyanonickelate K₄[Ni(CN)₄],bis(acrylonitrile)nickel(0), bis(1,5-cyclooctadiene)nickel and thederivatives comprising ligands from Group Va, such astetrakis(triphenylphosphine)nickel(0),

[0057] nickel compounds, such as the carboxylates (in particular theacetate), carbonate, bicarbonate, borate, bromide, chloride, citrate,thiocyanate, cyanide, formate, hydroxide, hydrophosphite, phosphite,phosphate and derivatives, iodide, nitrate, sulphate, sulphite,arylsulphonates and alkylsulphonates.

[0058] When the nickel compound used corresponds to an oxidation stateof the nickel of greater than 0, a reducing agent for the nickel isadded to the reaction medium, which reducing agent preferably reactswith the nickel under the conditions of the reaction. This reducingagent can be organic or inorganic. Mention may be made, as nonlimitingexamples, of NaBH₄, Zn powder, magnesium, KBH₄ and borohydrides.

[0059] When the nickel compound used corresponds to the 0 oxidationstate of nickel, a reducing agent of the type of those mentioned abovecan also be added but this addition is not essential.

[0060] When an iron compound is used, the same reducing agents aresuitable.

[0061] In the case of palladium, the reducing agents can be, inaddition, components of the reaction medium (phosphine, solvent,olefin).

[0062] The organic compounds comprising at least one ethylenic doublebond more particularly employed in the present process are diolefins,such as butadiene, isoprene, 1,5-hexadiene or 1,5-cyclooctadiene,aliphatic nitrites comprising ethylenic unsaturation, particularlylinear pentenenitriles, such as 3-pentenenitrile or 4-pentenenitrile,monoolefins, such as styrene, methylstyrene, vinylnaphthalene,cyclohexene or methylcyclohexene, and the mixtures of several of thesecompounds.

[0063] The pentenenitriles in particular can comprise amounts, generallyminor amounts, of other compounds, such as 2-methyl-3-butenenitrile,2-methyl-2-butenenitrile, 2-pentenenitrile, valeronitrile, adiponitrile,2-methylglutaronitrile, 2-ethylsuccinonitrile or butadiene, originating,for example, from the prior reaction for the hydrocyanation of butadieneto unsaturated nitrites.

[0064] This is because, during the hydrocyanation of butadiene, notinsignificant amounts of 2-methyl-3-butenenitrile and2-methyl-2-butenenitrile are formed with the linear pentenenitriles.

[0065] The catalytic system used for the hydrocyanation according to theprocess of the invention can be prepared before its introduction intothe reaction region, for example by addition to the phosphine of formula(I), alone or dissolved in a solvent, of the appropriate amount ofchosen transition metal compound and optionally of reducing agent. It isalso possible to prepare the catalytic system “in situ” by simpleaddition of the phosphine and the transition metal compound to thehydrocyanation reaction medium, before or after the addition of thecompound to be hydrocyanated.

[0066] The amount of compound of nickel or of another transition metalused is chosen in order to obtain a concentration, as mole of transitionmetal per mole of organic compounds to be hydrocyanated or isomerized,of between 10⁻⁴ and 1 and preferably between 0.005 and 0.5 mol of nickelor of the other transition metal employed.

[0067] The amount of phosphine of formula (I) used is chosen so that thenumber of moles of this compound with respect to 1 mol of transitionmetal is from 0.5 to 500 and preferably from 2 to 100.

[0068] Although the reaction is generally carried out without a solvent,it can be advantageous to add an inert organic solvent.

[0069] Mention may be made, as examples of such solvents, of aromatic,aliphatic or cycloaliphatic hydrocarbons.

[0070] The hydrocyanation reaction is generally carried out at atemperature of 10° C. to 200° C. and preferably of 30° C. to 120° C.

[0071] The process of the invention can be carried out continuously orbatchwise.

[0072] The hydrogen cyanide employed can be prepared from metalcyanides, in particular sodium cyanide, or cyanohydrins, such as acetonecyanohydrin.

[0073] The hydrogen cyanide is introduced into the reactor in thegaseous form or in the liquid form. It can also be dissolved beforehandin an organic solvent.

[0074] In the context of a batchwise implementation, it is in practicepossible to charge to a reactor, purged beforehand using an inert gas(such as nitrogen or argon), either a solution comprising all or aportion of the various constituents, such as the phosphine, thetransition metal compound, the possible reducing agent and the possiblesolvent, or the said constituents separately. Generally, the reactor isthen brought to the chosen temperature and then the compound to behydrocyanated is introduced. The hydrogen cyanide is then itselfintroduced, preferably continuously and unvaryingly.

[0075] When the reaction (the progress of which can be monitored by theassaying of withdrawn samples) is complete, the reaction mixture iswithdrawn after cooling and the reaction products are isolated, forexample, by distillation.

[0076] An improvement to the process for the hydrocyanation of compoundscomprising ethylenic unsaturation according to the present inventionrelates in particular to the hydrocyanation of the said nitrilecompounds comprising ethylenic unsaturation by reaction with hydrogencyanide and consists in using a catalytic system in accordance with thepresent invention with a cocatalyst comprising at least one Lewis acid.

[0077] The compounds comprising ethylenic unsaturation which can beemployed in this improvement are generally those which were mentionedfor the basic process. However, it is more particularly advantageous toapply it to the reaction for the hydrocyanation to dinitriles ofaliphatic nitrites comprising ethylenic unsaturation, in particular tolinear pentenenitriles, such as 3-pentenenitrile, 4-pentenenitrile andtheir mixtures.

[0078] These pentenenitriles can comprise amounts, generally minoramounts, of other compounds, such as 2-methyl-3-butenenitrile,2-methyl-2-butenenitrile, 2-pentenenitrile, valeronitrile, adiponitrile,2-methylglutaronitrile, 2-ethylsuccinonitrile or butadiene, originatingfrom the prior reaction for the hydrocyanation of butadiene and/or fromthe isomerization of 2-methyl-3-butenenitrile to pentenenitriles.

[0079] The Lewis acid used as cocatalyst makes it possible inparticular, in the case of the hydrocyanation of aliphatic nitritescomprising ethylenic unsaturation, to improve the linearity of thedinitriles obtained, that is to say the percentage of linear dinitrilewith respect to all the dinitriles formed, and/or to increase theactivity and the lifetime of the catalyst.

[0080] The term “Lewis acid” is understood to mean, in the present text,according to the usual definition, compounds which accept electronpairs.

[0081] It is possible in particular to employ the Lewis acids mentionedin the work edited by G. A. Olah, “Friedel-Crafts and RelatedReactions”, Volume I, pages 191 to 197 (1963).

[0082] The Lewis acids which can be employed as cocatalysts in thepresent process are chosen from the compounds of elements from GroupsIb, IIb, IIIa, IIIb, IVa, IVb, Va, Vb, VIb, VIIb and VIII of thePeriodic Table. These compounds are generally salts, in particularhalides, such as chlorides or bromides, sulphates, sulphonates,halosulphonates, perhaloalkylsulphonates, in particularfluoroalkylsulphonates or perfluoroalkylsulphonates, carboxylates andphosphates.

[0083] Mention may be made, as nonlimiting examples of such Lewis acids,of zinc chloride, zinc bromide, zinc iodide, manganese chloride,manganese bromide, cadmium chloride, cadmium bromide, stannous chloride,stannous bromide, stannous sulphate, stannous tartrate, indiumtrifluoromethylsulphonate, the chlorides or bromides of rare-earthelements, such as lanthanum, cerium, praseodymium, neodymium, samarium,europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium,ytterbium and lutetium, cobalt chloride, ferrous chloride or yttriumchloride.

[0084] It is, of course, possible to employ mixtures of Lewis acids.

[0085] Preference is very particularly given, among Lewis acids, to zincchloride, zinc bromide, stannous chloride, stannous bromide and zincchloride/stannous chloride mixtures.

[0086] The Lewis acid cocatalyst employed generally represents from 0.01to 50 mol per mole of transition metal compound, more particularly ofnickel compound, and preferably from 1 to 10 mol per mole.

[0087] As for the implementation of the basic process of the invention,the catalytic solution used for the hydrocyanation in the presence ofLewis acid can be prepared before its introduction into the reactionregion, for example by addition, to the reaction medium of the phosphineof formula (I), of the appropriate amount of chosen transition metalcompound, of the Lewis acid and optionally of the reducing agent. It isalso possible to prepare the catalytic solution “in situ” by simplemixing of these various constituents.

[0088] It is also possible, under the conditions of the hydrocyanationprocess of the present invention and in particular by carrying out thehydrocyanation in the presence of the catalyst described abovecomprising at least one phosphine of formula (I) and at least onetransition metal compound, to carry out, in the absence of hydrogencyanide, isomerization of 2-methyl-3-butenenitrile to pentenenitrilesand more generally of branched unsaturated nitrites to linearunsaturated nitrites.

[0089] The 2-methyl-3-butenenitrile subjected to isomerization accordingto the invention can be employed alone or as a mixture with othercompounds.

[0090] Thus, 2-methyl-3-butenenitrile can be used as a mixture with2-methyl-2-butenenitrile, 4-pentenenitrile, 3-pentenenitrile,2-pentenenitrile, butadiene, adiponitrile, 2-methylglutaronitrile,2-ethylsuccinonitrile or valeronitrile.

[0091] It is particularly advantageous to treat the reaction mixtureoriginating from the hydrocyanation of butadiene by HCN in the presenceof at least one phosphine of formula (I) and at least one compound of atransition metal, more preferably a compound of nickel in the 0oxidation state, as defined above.

[0092] In the context of this preferred alternative form, the catalyticsystem being already present for the reaction for the hydrocyanation ofbutadiene, it is sufficient to halt any introduction of hydrogen cyanideto allow the isomerization reaction to take place.

[0093] In this alternative form, it is possible, if appropriate, tocarry out a slight flushing of the reactor using an inert gas, such asnitrogen or argon, for example, in order to drive off the hydrocyanicacid which might still be present.

[0094] The isomerization reaction is generally carried out at atemperature of 10° C. to 200° C. and preferably of 60° C. to 120° C.

[0095] In the preferred case of an isomerization immediately followingthe reaction for the hydrocyanation of butadiene, it will beadvantageous to carry out the isomerization at the temperature at whichthe hydrocyanation was carried out.

[0096] As for the process for the hydrocyanation of compounds comprisingethylenic unsaturation, the catalytic system used for the isomerizationcan be prepared before its introduction into the reaction region, forexample by addition, to the reaction medium of the phosphine of formula(I), of the appropriate amount of chosen transition metal compound andoptionally of the reducing agent. It is also possible to prepare thecatalytic system “in situ” by simple mixing of these variousconstituents. The amount of transition metal compound and moreparticularly of nickel compound used and the amount of phosphine offormula (I) are the same as for the hydrocyanation reaction.

[0097] Although the isomerization reaction is generally carried outwithout a solvent, it can be advantageous to add an inert organicsolvent which can be that of the subsequent extraction. This is inparticular the case when such a solvent has been employed in thereaction for the hydrocyanation of butadiene which has been used toprepare the medium subjected to the isomerization reaction. Suchsolvents can be chosen from those which were mentioned above for thehydrocyanation.

[0098] However, the preparation of dinitrile compounds by hydrocyanationof an olefin such as butadiene can be carried out by using a catalyticsystem in accordance with the invention for the stages of formation ofthe unsaturated nitrites and the stage of isomerization above, it beingpossible for the reaction for the hydrocyanation of the unsaturatednitrites to dinitriles to be carried out with a catalytic system inaccordance with the invention or any other catalytic system alreadyknown for this reaction.

[0099] Likewise, the reaction for the hydrocyanation of the olefin tounsaturated nitrites and the isomerization of the latter can be carriedout with a catalytic system different from that of the invention, thestage of hydrocyanation of the unsaturated nitrites to dinitriles beingcarried out with a catalytic system in accordance with the invention.

[0100] The invention will be more clearly illustrated in the light ofthe examples given below by way of indication and illustration.

[0101] In these examples, the meanings of the abbreviations used aregiven below:

[0102] cod: 1,5-cyclooctadiene

[0103] 2M3BN: 2-methyl-3-butenenitrile

[0104] 2M2BN: 2-methyl-2-butenenitrile

[0105] 3PN: 3-pentenenitrile

[0106] 4PN: 4-pentenenitrile

[0107] ADN: adiponitrile

[0108] MGN: methyleneglutaronitrile

[0109] ESN: ethylsuccinonitrile

[0110] DN: dinitriles=ADN+MGN+ESN

[0111] AC: acetone cyanohydrin

[0112] EtPh: ethylbenzene

[0113] EG: ethylene glycol

[0114] DC (V): degree of conversion of the compound V to behydrocyanated or isomerized, equal to the ratio of the differencebetween the number of moles of the compound

[0115] V charged and the number of moles present at the end of thereaction to the number of moles charged

[0116] TY (U): true yield of the compound formed U=number of moles of Uformed/maximum number of moles of U, calculated with respect to thenumber of moles of the compound V charged

[0117] YD (U): selectivity for the compound U=TY (U)/DC (V)

[0118] L: linearity=YD (ADN)/[YD (ADN)+YD (MGN)+YD (ESN)]

[0119] GC : gas chromatography

[0120] mol: mole

[0121] mmol: millimole

EXAMPLES 1 and 2 Isomerization of 2M3BN to 3PN

[0122]

[0123] Procedure:

[0124] 20 mg (0.073 mmol, M=275 g/mol, 1.0 eq) of Ni (cod)₂ and 5.0 eqof PNP or PNA ligand are charged to a reactor equipped with a stirrerand placed under an argon atmosphere. Approximately 1 ml (810 mg,d=0.81, M=81.12 g/mol) of degassed 2M3BN is added. The mixture isstirred and maintained at a temperature of 100° C. in a closed systemfor 1 hour. The reaction medium is cooled to ambient temperature(approximately 20° C.). The concentrations of the various constituentsof the reaction medium are determined by analysis by GC (gaschromatography).

[0125] The results obtained and calculated from these analyses arecollated in Table I below: TABLE I Molar DC YD YD Ex. Ligand balance(2M3BN) (3 + 4PN) (2M2BN) 1 PNP 97% 87% 89% 6% 2 PNA 97% 48% 84% 8%

EXAMPLES 3 to 5 Hydrocyanation of 3PN to ADN

[0126]

[0127] Procedure:

[0128] The ligand L (5 eq), 3PN (30 eq), Ni(cod)₂ (1 eq), ZnCl₂ (1 eq),the degassed cosolvent or cosolvents and acetone cyanohydrin (30 eq) aresuccessively introduced at ambient temperature into a Schlenk tubemaintained under argon. The mixture is brought with stirring (600rev/min) to 65° C. for 2 hours and then brought back to ambienttemperature. 3 ml of acetone are introduced to neutralize the remainingHCN. The concentrations of the various components are determined by GCanalysis in order to calculate the various degrees of conversion and ofselectivity.

[0129] The results obtained and calculated from these analyses arecollated in Table II below: TABLE II Charges (mmoles) Results Ligand Ni-Solvents DC YD L Ex. L 3PN (cod)₂ ZnCl₂ AC (vol %) (3PN) (DN) (ADN) 3PNP 15 0.44 0.5 15 EtPh 13% 53% 75% (2.5) (10) 4 PNA 15.6 0.43 0.5 15.363% 82% 70% (2.5) 5 PNA 2.1 0.08 0.08 2.4 EG (26)   73.2%   65.4%  74.4% (0.4) EtPh (11)

EXAMPLE 6 Hydrocyanation of 3PN to ADN

[0130] Procedure:

[0131] 0.506 g (6.25 mmol, M=81 g/mol) of 3PN, 340 mg (0.93 mmol, M=366g/mol) of PNP, 1.96 g of degassed toluene, 56.5 mg (0.21 mmol, M=275g/mol) of Ni(cod)₂ and 50.1 mg (0.21 mmol, M=242 g/mol) of BPh₃ arecharged under argon to a 20 ml Schott tube equipped with a septum. Themixture is brought with stirring to 65° C. and 531 mg (6.24 mmol, M=85g/mol) of acetone cyanohydrin are injected via the septum and using asyringe driver at a flow rate of 0.19 ml/h. After reacting for 3 h, themixture is brought back to ambient temperature and neutralized to removethe remaining HCN. The concentrations of the various components aredetermined by GC analysis in order to calculate the various degrees ofconversion and of selectivity.

[0132] The results obtained and calculated from these analyses arecollated in Table III below: TABLE III Linearity Ex. DC (3PN) YD(mononitriles) YD (dinitriles) (ADN) 6 35% 91.8% 12.4% 69%

1. Process for the hydrocyanation of organic compounds comprising atleast one ethylenic bond by reaction with hydrogen cyanide in thepresence of a catalytic system comprising a transition metal and anorganophosphorus ligand, characterized in that the ligand is a phosphinecorresponding to the following general formula (I):

in which: E represents O or S; n represents 0 or 1; R₁, R₄, R₅ and R₆,which are identical or different, represent a hydrogen atom; anoptionally substituted, saturated or unsaturated, aliphatichydrocarbonaceous radical comprising 1 to 40 carbon atoms, thehydrocarbonaceous chain of which is optionally interrupted by aheteroatom; an optionally substituted, monocyclic or polycyclic,saturated, unsaturated or aromatic, carbocyclic or heterocyclic radical;or a saturated or unsaturated, aliphatic hydrocarbonaceous radical, thehydrocarbonaceous chain of which is optionally interrupted by aheteroatom and carries a carbocyclic or heterocyclic radical as definedabove, the said radical optionally being substituted; or else R₄ and R₅form, together with the carbon atoms which carry them, an optionallysubstituted, saturated or unsaturated, carbocyclic monocycle preferablyhaving from 5 to 7 carbon atoms; R₂ represents a hydrogen atom or the Xradical; R₃ represents the X radical or the Y radical; it beingunderstood that one and one alone of the R₂ and R₃ substituentsrepresents the X radical; X being chosen from a monocyclic or bicyclic,aromatic carbocyclic or heterocyclic radical having from 2 to 20 carbonatoms; a 1-alkenyl radical optionally exhibiting one or more additionalunsaturations in the hydrocarbonaceous chain and having from 2 to 12carbon atoms; a 1-alkynyl radical optionally exhibiting one or moreadditional unsaturations in the hydrocarbonaceous chain and having from2 to 12 carbon atoms; or a —CN, [(C₁-C₁₂)alkyl]-carbonyl,[(C₃-C₁₈)aryl]carbonyl, [(C₁-C₁₂)alkoxy]-carbonyl,[(C₆-C₁₈)aryloxy]carbonyl, carbamoyl, [(C₁-C₁₂)alkyl]carbamoyl or[di(C₁-C₁₂) alkyl]carbamoyl radical; and Y taking any one of themeanings of R₁, with the exception of a hydrogen atom; R₇ has themeaning of R₁, R₄, R₅ and R₆ or represents a hydrocarbonaceous radicalcomprising a carbonyl functional group or a radical of followingformulae:

in which, A represents a hydrogen atom; ( C₁-C₁₀)alkyl; or (C₆-C₁₀)arylor (C₆-C₁₀)aryl(C₁-C ₁₀)alkyl in which the aryl part is optionallysubstituted by one or more radicals chosen from (C₁-C₆)alkyl,(C₁-C₆)alkoxy, trifluoromethyl, halogen, di(C₁-C₆)alkylamino, (C₁-C₆)alkoxycarbonyl, carbamoyl, (C₁-C₆)alkylaminocarbonyl and di(C₁-C₆)alkylaminocarbonyl; —Ar₁—Ar₂— represent: either the divalent radical offormula:

in which each of the phenyl nuclei is optionally substituted by one ormore Z groups as defined below; or the divalent radical of formula:

in which each of the phenyl nuclei is optionally substituted by one ormore Z groups as defined below; Z represents (C₁-C₆)alkyl,(C₁-C₆)alkoxy, trifluoromethyl, halogen, (C₁-C₆)alkoxycarbonyl,di(C₁-C₆)alkylamino, (C₁-C₆)alkylaminocarbonyl ordi(C₁-C₆)alkylaminocarbonyl; R₈ and R₉, which are identical ordifferent, represent a substituted or unsubstituted aryl radical. 2.Process according to claim 1, characterized in that the phosphinecompounds are those corresponding to the formula (I) in which: R₁, R₂,R₄, R₅ and R₆ independently represent a hydrogen atom or else a Tradical chosen from: a saturated or unsaturated aliphatichydrocarbonaceous radical having from 1 to 12 carbon atoms, thehydrocarbonaceous chain of which is optionally interrupted by aheteroatom chosen from O, N and S; a monocyclic carbocyclic radicalwhich is saturated or which comprises 1 or 2 unsaturations in the ring,having from 3 to 8 carbon atoms; a saturated or unsaturated bicycliccarbocyclic radical composed of 2 single rings condensed to one another,each single ring optionally comprising 1 to 2 unsaturations andexhibiting from 3 to 8 carbon atoms; a mono- or bicyclic (C₆-C₁₀)aromatic carbocyclic radical; a saturated, unsaturated or aromatic 5- to6-membered monocyclic heterocyclic radical comprising 1 to 3 heteroatomschosen independently from N, O and S; a saturated, unsaturated oraromatic bicyclic heterocyclic radical composed of two 5- to 6-memberedsingle rings condensed to one another, each single ring comprising 1 to3 heteroatoms chosen independently from O, N and S; and a saturated orunsaturated aliphatic hydrocarbonaceous radical having from 1 to 12carbon atoms, the hydrocarbonaceous chain of which carries a carbocyclicor heterocyclic monocyclic radical as defined above, the said T radicaloptionally being substituted.
 3. Process according to claim 1 or 2,characterized in that X is chosen from a (C₂-C₆)alkenyl group, a(C₂-C₆)alkynyl group, phenyl, naphthyl, thienyl, furyl, pyrrolyl,imidazolyl, pyrazolyl, thiazolyl, oxazolyl, pyridyl, pyrazinyl,pyridazinyl, isothiazolyl, isoxazolyl, benzofuryl, benzothienyl,indolyl, isoindolyl, indolizinyl, indazolyl, purinyl, quinolyl,isoquinolyl, benzoxazolyl, benzothiazolyl and pteridinyl.
 4. Processaccording to one of claims 1 to 3, characterized in that the T radicalis substituted by a group chosen from the following group comprising:(C₁-C ₆) alkyl, (C₂-C₆) alkenyl, (C ₁-C₆) alkoxy or (C₂-C₆)acyl; aradical chosen from: —R_(a)—COOR_(b), —R_(a)—NO₂, —R_(a)—CN,di(C₁-C₆)alkylamino, di(C₁-C₆)alkylamino (C₁-C₆)alkyl,—R_(a)—CO—N(R_(b))₂, —R_(a)-hal, —R_(a)CF₃ and —O—CF₃ (in which R_(a)represents a bond or (C₁-C₆)alkylene, R_(b), which are identical ordifferent, represent a hydrogen atom or (C₁-C₆)alkyl, and hal representshalogen); or alternatively the radical:

where R_(d) is chosen from (C₁-C₆)alkyl, (C₂-C₆)alkenyl, (C₁-C₆)alkoxy,(C₂-C₆)acyl, —R_(a)—COOR_(b), —R_(a)—NO₂, —R_(a)—CN, di (C₁-C₆)alkylamino, di(C₁-C₆) alkylamino (C₁-C₆) alkyl, —R_(a)—CO—N(R_(b))₂,—R_(a)-hal, —R_(a)—CF₃ and —O—CF₃ (in which R_(a), R_(b) and hal are asdefined above); m represents an integer between 0 and 5; R_(c)represents a bond, (C₁-C₆) alkylene, —O—, —CO—, —COO—, —NR_(b)—,—CO—NR_(b)—, —S—, —SO₂— or —NR_(b)—CO—, R_(b)being as defined above. 5.Process according to one of the preceding claims, characterized in thatthe phosphine corresponds either to the following formula II or to thefollowing formula III: Formula (II):

Formula (III):


6. Process according to one of the preceding claims, characterized inthat the transition metal compounds are chosen from nickel, palladiumand iron compounds.
 7. Process according to one of the preceding claims,characterized in that the preferred transition metal compounds are thoseof nickel and are chosen from: compounds in which the nickel is in thezero oxidation state, such as potassium tetracyanonickelate K₄[Ni(CN)₄],bis(acrylonitrile)nickel(0), bis(1,5-cyclooctadiene)nickel and thederivatives comprising ligands from Group Va, such astetrakis(triphenylphosphine)nickel(0); nickel compounds, such as thecarboxylates, carbonate, bicarbonate, borate, bromide, chloride,citrate, thiocyanate, cyanide, formate, hydroxide, hydrophosphite,phosphite, phosphate and derivatives, iodide, nitrate, sulphate,sulphite, arylsulphonates and alkylsulphonates.
 8. Process according toone of the preceding claims, characterized in that the organic compoundscomprising at least one ethylenic double bond are chosen from diolefins,such as butadiene, isoprene, 1,5-hexadiene or 1,5-cyclooctadiene,aliphatic nitriles comprising ethylenic unsaturation, particularlylinear pentenenitriles, such as 3-pentenenitrile or 4-pentenenitrile,monoolefins, such as styrene, methylstyrene, vinylnaphthalene,cyclohexene or methylcyclohexene, and the mixtures of several of thesecompounds.
 9. Process according to one of the preceding claims,characterized in that the amount of nickel compound or compound ofanother transition metal used is chosen so that there is, per mole oforganic compound to be hydrocyanated or isomerized, between 10⁻⁴ and 1mol of nickel or of the other transition metal employed and in that theamount of phosphine of formula (I) used is chosen so that the number ofmoles of this compound with respect to 1 mol of transition metal is from0.5 to
 500. 10. Process according to one of the preceding claims,characterized in that the hydrocyanation reaction is carried out at atemperature of 10° C. to 200° C .
 11. Process according to one of thepreceding claims for the hydrocyanation to dinitriles of nitrilecompounds comprising ethylenic unsaturation by reaction with hydrogencyanide, characterized in that the reaction is carried out in thepresence of a catalytic system comprising at least one compound of atransition metal, at least one phosphine of formula (I) and a cocatalystcomprising at least one Lewis acid.
 12. Process according to claim 11,characterized in that the nitrile compounds comprising ethylenicunsaturation are chosen from aliphatic nitriles comprising ethylenicunsaturation comprising linear pentenenitriles, such as3-pentenenitrile, 4-pentenenitrile and their mixtures.
 13. Processaccording to claim 12, characterized in that the linear pentenenitrilescomprise amounts, generally minor amounts, of other compounds, such as2-methyl-3-butenenitrile, 2-methyl-2-butenenitrile, 2-pentenenitrile,valeronitrile, adiponitrile, 2-methylglutaronitrile,2-ethylsuccinonitrile or butadiene.
 14. Process according to one ofclaims 11 to 13, characterized in that the Lewis acid employed ascocatalyst is chosen from the compounds of the elements from Groups Ib,IIb, IIIa, IIIb, IVa, IVb, Va, Vb, VIb, VIIb and VIII of the PeriodicTable.
 15. Process according to one of claims 11 to 14, characterized inthat the Lewis acid is chosen from the salts chosen from the group ofthe halides, sulphates, sulphonates, haloalkylsulphonates,perhaloalkylsulphonates, carboxylates and phosphates.
 16. Processaccording to one of claims 11 to 15, characterized in that the Lewisacid is chosen from zinc chloride, zinc bromide, zinc iodide, manganesechloride, manganese bromide, cadmium chloride, cadmium bromide, stannouschloride, stannous bromide, stannous sulphate, stannous tartrate, indiumtrifluoromethylsulphonate, the chlorides or bromides of rare-earthelements, such as lanthanum, cerium, praseodymium, neodymium, samarium,europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium,ytterbium and lutetium, cobalt chloride, ferrous chloride, yttriumchloride and their mixtures.
 17. Process according to one of claims 11to 16, characterized in that the Lewis acid employed represents from0.01 to 50 mol per mole of transition metal compound.
 18. Processaccording to one of claims 1 to 17, characterized in that theisomerization to pentenenitriles of the 2-methyl-3-butenenitrile presentin the reaction mixture originating from the hydrocyanation of butadieneis carried out in the absence of hydrogen cyanide, the isomerizationbeing carried out in the presence of a catalyst comprising at least onephosphine of formula (I) and at least one compound of a transitionmetal.
 19. Process according to claim 18, characterized in that the2-methyl-3-butenenitrile subjected to isomerization is employed alone oras a mixture with 2-methyl-2-butenenitrile, 4-pentenenitrile,3-pentenenitrile, 2-pentenenitrile, butadiene, adiponitrile,2-methylglutaronitrile, 2-ethylsuccinonitrile or valeronitrile. 20.Process according to either of claims 18 and 19, characterized in thatthe isomerization reaction is carried out at a temperature of 10° C. to200° C. cm
 21. Process according to one of claims 18 to 20,characterized in that the isomerization to pentenenitriles of2-methyl-3-butenenitrile is carried out in the presence of at least onecompound of a transition metal, of at least one phosphine of formula (I)and a cocatalyst comprising at least one Lewis acid.